Fasting's Metabolic Effects

Fasting can reset cells' metabolism, helping the body burn fat and lose weight even without dieting.

Americans’ poor eating habits and lack of physical activity continue to undermine any progress on the rising tide of metabolic diseases such as heart disease, diabetes and obesity that plague them, but a new study suggests there is a dietary intervention that may head off these diseases. Intermittent fasting may kickstart your metabolism and help you burn body fat.

Fasting has been known to slow aging and give the body a chance to rest and reset itself. Researchers from the University of Toronto subjected a group of mice to 16 weeks of intermittent fasting in an effort to understand what happens in the body on a molecular level when it is given a chance to take a vacation from ingesting and digesting food.

Not only did the mice in the fasting group weigh less than the mice in the group that ate every day, they had less white fat and more brown fat, the type involved in producing body heat and burning energy.

One group of mice received no food for one day and then were fed for two days. This intermittent fasting pattern was repeated for 16 weeks. The other group was fed every day. Both groups received the same number of calories over the 16 weeks of the study.
Not only did the mice in the fasting group weigh less than the mice in the group that ate every day, they had less white fat and more brown fat, the type involved in producing body heat and burning energy. Glucose and insulin levels in the fasting mice were more stable, as well.

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Intermittent fasting produced beneficial changes in gene pathways that are part of the immune system and the body’s response to inflammation. For example, it activated anti-inflammatory macrophages, a type of white blood cell that stimulates fat cells to burn body fat by generating heat.

“Intermittent fasting without a reduction in calorie intake can be a preventative and therapeutic approach against obesity and metabolic disorders,” said researcher, Kyoung-Han Kim, in a statement.

The study gives us a better understanding of why fasting periodically can be so good for the body. More research is needed to see if this dietary intervention works the same way in humans and to determine if it could help prevent obesity and other metabolic diseases, but fasting appears to be a relatively easy, not to mention inexpensive, way one can possibly help bring the body's metabolism into a better balance.